Most of the catfish I keep and have mentioned before consume algae wholly or as part of their diet. I use various prepared manufactured foods that contain algae that I feed to my catfish, but I do prefer that they have a chance to eat the real mccoy. It’s quite a challenge to grow alage of the correct type and quantity to satisfy the vegetarian catfish.
I’ve found that using a Sunglow & PowerGlo tube in combination stimulates high algal growth on two shelves in my fish house. I harvest the algae produced and use it as a food source in other catfish tanks and on occasion my catfish have an algae holiday.
I have also found with experimentation, that Bristlenose catfish Ancistrus sp., “Plecos” and other L numbers, become lazy, at eating natural alage in the aquarium, if they are reguarly feed on algae wafers!